Furnace grate



IIJ

FURNACE GRATE A. W HULSON Filed Nov. 2, 1931 Jan. 31, 1933.

Patented Jan. 31,

' UNlTED STATES l,895,5ll

ARTHUR w. HULSON, 01' mm IOWA GBA'IE Application filed November 2, 1981. Serial Ho. 572,650.

The invention relates to improvements in furnace grates designed primaril for burning such fuels as lignite and slac in which an abundance of air must be supplied to the 5 fire and distributed uniformly throughout the grate area.

It is the principal object of the invention to provide a novel and advantageous construction with which danger of the fuel falling through the grate, is minimized.

It is a further object to provide a new and improved grate structure of the type referred to, embodying novel construction whereby a plurality of tortuous, preferably zlg-zag, air passages extend from the lower to the upper side .of the grate, said tortuouspassages n suring effective heating of the air before discharge thereof into fire and also tending to lessen the dropping of fuel through the grate.

Another object of the invention is to provide grate fingers of unique construction for forming the air passages, gers be embodied in a grate'having finger bars upon which they are mounted, or in a chain link grate.-

Yet another aim is to provide a construction which is simple and nexpensive, may

therefore be manufactured and marketed at small cost, andwill permit quick and easy removal of damaged fingers, and substitution of new ones.

With the foregoing in view, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished by reference to the accoman drawin p is a top plan view showin two of the fingers in operative relation with each other.

Fig. 2 is a side elevation of one of the fingers. I

Fig. 3 is a vertical transverse sectional view on line 3-3 of Fig. 2 showing two of the fi'ngers in operative relation.

Fig. 4 is a fragmentary perspective view showing portions of two of the fingers in juxtaposition.

A preferred construction has been shown and will be rather specifically described, with 50 the understanding however that within the whether said finscopeof the invention as claimed, variations may be made. For instance, while I have shown the tortuous or zig-zag air passages formed by intermeshing upper and lower rows of lugs upon adjacent fingers, the lugs of any fin er being separate from those of the other gers, it will be obvious that an equivalent construction, insofar as certain advantages are concerned, could be attained by integrally joining the lugs of any section all with the lugs of adjacent sections. Hence, the term finger as used herein is not to be restricted as a finger entirely separate from an adjacent finger, and moreover, such expressions as intermeshin lugs on adjacent fingers, are not necessar' y to be construed as meaning a structure in which the lugs of any finger are entirely separate from the lugs of adjacent fingers.

or purposes of illustration, two finger plates F are shown, and as they are duplicates, a description of one will sufiice, the reference characters used in the description however, being placed upon both fingers.

The finger F embodies a central long-i tudinal web 5 whose lower portion is herein shown as thickened at 6 and provided with a hub 7 for engagement with a finger bar. The finger F however may be constructed to form a portion of a chain link grate, as will be understood to those skilled in the art, without further explanation.

Integral with one vertical sideof the web 5, I provide an upper horizontal row of lateral lugs 8 whose upper sides 9 are preferably plain and horizontal, with the exception of ribs 10 along their transverse edges, said ribs being only of suflicient height to have a tendency to support the fuel slightly above the faces 9, so that air from the air passages may more readily pass under said fuel. The lugs 8 are spaced apart longitudinally of the finger F and said lugs are of a width slightly less than the width of the spaces which intervene between them. The opposed vertical sides of these? .gs are preferably flat and plain, the outer sides of said lugs may well be plain and para llel with the web 5, and the lower ends 11 of said lugs preferably decline toward the web 5.

' tions of a chain link and Integral with the aforesaid one side of the web 5, is a lower row of lateral lugs 12, said lugs 12 being spaced apart longitudinally of the finger F and'being of a width slightly less than the width of the spaces which intervene between the lugs. Preferably, the lugs 12 extend between the lower portions of the lugs 8, the overlapping parts of the upper and lower lugs being integrally joined to each other. It is also preferable that the upper side 13 of each lug 12 be inclined toward the web 5, and that the lower side 14 of the lug be declined toward saidweb.

Integral with the opposite side of the web 5, are upper and lower rows of lugs 8 and 12 respectively, which correspond in structure and relation to the lugs 8 and 12. The lugs 8 are in staggered relation with the lugs 8 and staggered relation also exists between the lugs 12 and 12.

When the fingers F are relatively assembled to form the grate, the hubs 7 so space the upper portions of said fingers, that the outer sides or ends of the lugs of any web 5, will be spaced from the next adjacent web, and.

the lugs of any finger will be spaced from the lugs ofthe next adjacent finger. The spacing referred to, is of course in a direction transverse to the length of the fingers F, for the various lugs 8 and 8 partially intermesh with each other, and the same is true of the lugs 12 and 12. It will'thus be seen that between any two adjacent fingers F, air discharge orifices 15 are provided at the upper face of the grate, and that tortuous, zig-zag air passages 16 lead to said' orifices from the lower side of the grate. It is thus insured that all air discharged through the grate face, shall be highly heated as well as uniformly distributed, and at the same time, there is little liability of' the fuel. falling through the grate.

I am aware that parallel grate-forming plates disposed side to side in vertical planes having rows of intermeshing lugs adjacent their upper edges, have heretofore been provided. However, they allow unobstructed upward rush of air and do not provide the tortuous air-heating passages which my invention embodies, due to the provision of the lower rows of intermeshing lugs directly below the spaces between the upper lugs. These lower lugs prevent direct vertical rush of air to the air discharge orifices at the base of the grate and hence insure that said air shall be more highly heated by contact with the grate. Hence, the air supports more eflicient combustion.

Attention is again invited to the following:The improved finger structure may be embodied in a grate in which the fingers are carried by finger bars, or may constitute porgrate. The fingers may in some instances be formed integrally with each other instead of separate. Further- :tween them; the lower with respect to the upper lugs and extending of said web, the lugs more, the exact shaping of lugs and the like herein disclosed, and the exact manner of mounting the fingers, followed.

The finger-locking means L is claimed in my U. S. application Serial N 0. 572,652, filed Nov. 2, 1931.

V I claim 1. A grate finger comprising a central vertical longitudinal web, an upper rowof lateral lugs integral with one vertical side of said web and spaced apart longitudinally of said web, the lugs being of a width slightly less than the width of the spaces intervening between them; a lower row of lateral lugs integral with said one side of the web and likewise spaced apart longitudinally of said web, the lower lugs being of a width slightly less than the width of the spaces intervening between them; the lower lugs being staggered with respect to the upper lugs; and additional upper and lower rows of lugs integral with the other side of said web and corresponding in structure and relation with the aforesaid lugs; the lugs at either side of the web being adapted to co-operate with those of an adjacent finger to provide tortuous air-heating passages.

2. A grate finger comprising a central vertical longitudinal web, an upper row of lateral lugs integral with one vertical side of said web and spaced apart longitudinally of said web, the lugs being of a width slightly less than the width of the spaces intervening between them; a lower row of lateral lugs integral with said one side of the web and likewise spaced apart longitudinally of said web, the lower lugs being of a width slightly less than the width of the spaces intervening belugs being staggered between the latter; and additional upper and lower rows of lugs integral with the other side of said web and corresponding in structure and relation with the aforesaid lugs; the lugs at either side of the web being adapted to co-operate with those of an adjacent need not be strictly finger to'provide tortuous air-heating passages.

3. A grate finger comprising a central vertical longitudinal web, an upper row of lateral lugs integral with one vertical side of said web and spaced apart longitudinally being of a width slightly less than the width of the spaces intervening between them; a lower row of lateral lugs integral with said one side of the web and likewise spaced apart longitudinally of said web, the lower lugs being of a width slightly less than the width of the spaces intervenin g between them; the lower lugs being staggered with respect to the upper lugs and extending between the latter; the lower sides of all of said lugs being declined toward said web; the upper sides of said lower lugs being inclined toward said web; the upper sides of said upper lugs constituting fuel supports; and additional upper and lower rows of lugs integral with the other side of said web and corresponding in structure and relation with the aforesaid lugs; the lugs at either side of said web being adapted to partially intermesh with those of an adjacent finger to provide tortuous air-heating passages.

4. A grate finger comprising acentral vertical longitudinal web, an upper row of lateral lugs integral with one vertical side of said web and spaced apart longitudinally of said web, the lugs being of a width slightly less than the width of the spaces intervening between them; a lower row of lateral lugs integral with said one side of the web and likewise spaced apart longitudinally of said web, the lower lugs being of a width slightly less than the width of the spaces intervening between them; the lower lugs being staggered with respect to the upper lugs; and additional upper and lower rows of lugs integral with the other side of said web and corresponding in structure and relation with the aforesaid lugs; the two upper rows of lugs having upstanding ribs along their transverse edges to support the fuel slightly above their upper sides.

5. Ina grate, adjacent fingers having central webs provided with upper rows of partially intermeshing lateral lugs at their upper portions, the outer ends of said lugs of any finger being spaced from the webs of adjacent fingers to provide air discharge orifices, and additional rows of partially intermeshing lateral lugs on said webs disposed below the spacesbetween the upper lugs to prevent direct vertical rush of air to said orifices, the outer ends of the lower lugs of any finger being spaced from the webs of adjacent fingers to permit ascent of air.

6. In a grate, adjacent fingers provided with vertically spaced rows of lateral'par-' tially intermeshing lugs having beveled ends which co-operate. in providing zig-zag airheating passages from the lower to the upper side of the grate. In testimony whereof I afiix my signature.

ARTHUR W. HULSON. 

